Re: [PATCH 0/3] target/arm: More HCR_EL2.TIDx fixes

[Peter Maydell]

On Thu, 28 Nov 2019 at 16:17, Marc Zyngier <address@hidden> wrote:
>
> I started looking the rest of the missing TIDx handling,
> and this resulted in the following patches.
>
> There is still one thing I'm a bit puzzled by though:
>
> HCR_EL2.TID0 mandates trapping of the AArch32 JIDR
> register, but I couldn't find a trace of it in the QEMU
> code, and trying to read it seems to generate an exception.
>
> It isn't like anyone is going to miss it, but I wonder if
> it should be implemented... It could also be that I'm missing
> the obvious and that my testing is broken! ;-)

Hmm, I was under the impression that we correctly implemented
'trivial Jazelle', but we obviously missed some of it
(we do have the handling of BXJ insns).
We should, yes, ideally, have RAZ/WI implementations
of JIDR, JMCR and JOSCR.

We also I think don't get right the fiddly detail about
attempting an exception return with SPSR.J set, but that's
not worth messing about with IMHO.

thanks
-- PMM